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  1. 11 Jan, 2007 1 commit
  3. 07 Dec, 2006 1 commit
    • Christoph Lameter's avatar
      [PATCH] Get rid of zone_table[] · 89689ae7
      Christoph Lameter authored 
      
The zone table is mostly not needed.  If we have a node in the page flags
then we can get to the zone via NODE_DATA() which is much more likely to be
already in the cpu cache.

In case of SMP and UP NODE_DATA() is a constant pointer which allows us to
access an exact replica of zonetable in the node_zones field.  In all of
the above cases there will be no need at all for the zone table.

The only remaining case is if in a NUMA system the node numbers do not fit
into the page flags.  In that case we make sparse generate a table that
maps sections to nodes and use that table to to figure out the node number.
 This table is sized to fit in a single cache line for the known 32 bit
NUMA platform which makes it very likely that the information can be
obtained without a cache miss.

For sparsemem the zone table seems to be have been fairly large based on
the maximum possible number of sections and the number of zones per node.
There is some memory saving by removing zone_table.  The main benefit is to
reduce the cache foootprint of the VM from the frequent lookups of zones.
Plus it simplifies the page allocator.

[akpm@osdl.org: build fix]
Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      89689ae7
  5. 01 Oct, 2006 3 commits
  7. 29 Sep, 2006 2 commits
    • Chandra Seetharaman's avatar
      [PATCH] call mm/page-writeback.c:set_ratelimit() when new pages are hot-added · 2d1d43f6
      Chandra Seetharaman authored 
      
ratelimit_pages in page-writeback.c is recalculated (in set_ratelimit())
every time a CPU is hot-added/removed.  But this value is not recalculated
when new pages are hot-added.

This patch fixes that problem by calling set_ratelimit() when new pages
are hot-added.

[akpm@osdl.org: cleanups]
Signed-off-by: default avatarChandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      2d1d43f6
    • Paul Jackson's avatar
      [PATCH] cpuset: top_cpuset tracks hotplug changes to node_online_map · 38837fc7
      Paul Jackson authored 
      
Change the list of memory nodes allowed to tasks in the top (root) nodeset
to dynamically track what cpus are online, using a call to a cpuset hook
from the memory hotplug code.  Make this top cpus file read-only.

On systems that have cpusets configured in their kernel, but that aren't
actively using cpusets (for some distros, this covers the majority of
systems) all tasks end up in the top cpuset.

If that system does support memory hotplug, then these tasks cannot make
use of memory nodes that are added after system boot, because the memory
nodes are not allowed in the top cpuset.  This is a surprising regression
over earlier kernels that didn't have cpusets enabled.

One key motivation for this change is to remain consistent with the
behaviour for the top_cpuset's 'cpus', which is also read-only, and which
automatically tracks the cpu_online_map.

This change also has the minor benefit that it fixes a long standing,
little noticed, minor bug in cpusets.  The cpuset performance tweak to
short circuit the cpuset_zone_allowed() check on systems with just a single
cpuset (see 'number_of_cpusets', in linux/cpuset.h) meant that simply
changing the 'mems' of the top_cpuset had no affect, even though the change
(the write system call) appeared to succeed.  With the following change,
that write to the 'mems' file fails -EACCES, and the 'mems' file stubbornly
refuses to be changed via user space writes.  Thus no one should be mislead
into thinking they've changed the top_cpusets's 'mems' when in affect they
haven't.

In order to keep the behaviour of cpusets consistent between systems
actively making use of them and systems not using them, this patch changes
the behaviour of the 'mems' file in the top (root) cpuset, making it read
only, and making it automatically track the value of node_online_map.  Thus
tasks in the top cpuset will have automatic use of hot plugged memory nodes
allowed by their cpuset.

[akpm@osdl.org: build fix]
[bunk@stusta.de: build fix]
Signed-off-by: default avatarPaul Jackson <pj@sgi.com>
Signed-off-by: default avatarAdrian Bunk <bunk@stusta.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      38837fc7
  9. 06 Aug, 2006 3 commits
  11. 30 Jun, 2006 1 commit
  13. 27 Jun, 2006 5 commits
  15. 23 Jun, 2006 3 commits
  17. 31 May, 2006 1 commit
  19. 01 May, 2006 1 commit
  21. 09 Mar, 2006 1 commit
  23. 06 Jan, 2006 1 commit
  25. 14 Dec, 2005 1 commit
  27. 30 Oct, 2005 3 commits